1. Field of the Invention
This invention relates to the field of jet entangling. The process of jet entangling, which is also called hydroentangling, hydraulic entangling, water jet needling, tanglelacing and spunlacing, is accomplished by forcing a liquid, usually water, at high pressures through nozzles or orifices to form fine columnar streams and directing a curtain of these streams or jets onto a fibrous web. The fibrous web to be treated is passed on a supporting screen through the curtain of water jets whereby the fibers are entangled to form a coherent textile web without the use of binders or resins. While the physical process of entanglement is not completely understood, it is believed that the turbulent breakup of the fine liquid steams as they impinge on and pass over the fibers in the web and the strands of the supporting screen causes physical intertwining of the fibers. The supporting screen can be of a suitable open area to impart its pattern on the entangled fabric giving a textile-like appearance, or the screen can be of sufficiently fine mesh to give a uniform, smooth appearance to the web.
The uniformity of product quality generated by the jet entangling process is directly affected by two variables, namely, (1) the quality of the supporting screen, and (2) the quality of the liquid jets. The present invention relates to the generation of high quality jets, which depends primarily on the uniform distribution of liquid to the nozzle strip and the precise filtering of the liquid medium.
2. Description of the Prior Art
U.S. Pat. Nos. 3,508,308 and 4,069,563 provide a general background description of the process of jet entangling.
U.S Pat. No. 3,403,862 discloses a jet manifold for tanglelacing textile-like fabrics. The apparatus disclosed in this patent includes a nozzle strip secured in place by a slotted retaining plate which is bolted to the manifold body Liquid is delivered to the nozzle strip from a chamber which is fed through a series of drilled holes to a delivery tube.
U.S. Pat. No. 3,613,999 discloses an apparatus for jetting liquid onto a fibrous web which consists of an elongated body having a longitudinal chamber therein. A nozzle strip is enclosed within a cartridge device which can be inserted into the longitudinal chamber in the elongated body The cartridge device has a slot in the bottom which aligns with a corresponding slot within the elongated body permitting the passage of liquid jets. The cartridge device has an open portion facing upwardly which has bolted thereto a filter through which pressurized liquid is supplied Removal of the nozzle strip for cleaning is accomplished by first removing the cartridge device from the elongated body and then removing a series of bolts and the filter device.
The devices disclosed in U.S. Pat. Nos. 3,403,862 and 3,613,999 have several disadvantages. These disadvantages include (1) the incomplete and non-uniform distribution of liquid to the nozzle strips and (2) the lengthy disassembly time required for the removal of the nozzle strips for cleaning. Incomplete a n d ineffective liquid distribution to the orifices in the nozzle strip result in turbulence and improper entry of liquid into the nozzle orifices which results in noncircular and/or deflected jets yielding streaks in the textile-like web. The downtime required to clean the nozzle strips is directly related to the ease with which the strip can be removed from the device and hence the number of bolts which must be removed to gain access to the strip.
Other patents relating to jet entanglement devices and processes are U.S. Pat. Nos. 3,485,706; 3,498,874; 3,494,821; 3,768,121; 3,787,932; 3,837,046; 4,024,612; 4,666,390; and 4,718,152.